Add a missing attribute to example.

We are describing that very attribute, so it should have been there to
begin with.
Merge pull request #125 from TekHus/master

Fixed issue with platform docs
Merge pull request #594 from KevWright/master

Fixed issue with platform docs
Added content for Mission Portal Alerts
Added images and update text for new alerts
Merge pull request #126 from TekHus/alerts

Added content for making new alerts
Merge pull request #595 from KevWright/master

Added content for making new alerts
Merge pull request #591 from kacfengine/home_bundle_inherit_fix

Add a missing attribute to example.
broke off new file from writing policy tutorial
Merge branch 'master' of https://github.com/cfengine/documentation